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Alekseyev AB, Liebermann HP, Buenker RJ. Potential energy surfaces for ground and excited electronic states of the CF3I molecule and their relevance to its A-band photodissociation. Phys Chem Chem Phys 2013; 15:6660-6. [DOI: 10.1039/c3cp44237c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Papanastasiou DK, Feierabend KJ, Burkholder JB. Cl2O photochemistry: Ultraviolet/vis absorption spectrum temperature dependence and O(3P) quantum yield at 193 and 248 nm. J Chem Phys 2011; 134:204310. [DOI: 10.1063/1.3592662] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hancock G, Horrocks SJ, Ritchie GAD, Helden JHV, Walker RJ. Time-Resolved Detection of the CF3 Photofragment Using Chirped QCL Radiation. J Phys Chem A 2008; 112:9751-7. [DOI: 10.1021/jp804849m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- G. Hancock
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - S. J. Horrocks
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - G. A. D. Ritchie
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - J. H. van Helden
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - R. J. Walker
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
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Pope FD, Hansen JC, Bayes KD, Friedl RR, Sander SP. Ultraviolet Absorption Spectrum of Chlorine Peroxide, ClOOCl. J Phys Chem A 2007; 111:4322-32. [PMID: 17474723 DOI: 10.1021/jp067660w] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The photolysis of chlorine peroxide (ClOOCl) is understood to be a key step in the destruction of polar stratospheric ozone. This study generated and purified ClOOCl in a novel fashion, which resulted in spectra with low impurity levels and high peak absorbances. The ClOOCl was generated by laser photolysis of Cl2 in the presence of ozone, or by photolysis of ozone in the presence of CF2Cl2. The product ClOOCl was collected, along with small amounts of impurities, in a trap at about -125 degrees C. Gas-phase ultraviolet spectra were recorded using a long path cell and spectrograph/diode array detector as the trap was slowly warmed. The spectrum of ClOOCl could be fit with two Gaussian-like expressions, corresponding to two different electronic transitions, having similar energies but different widths. The energies and band strengths of these two transitions compare favorably with previous ab initio calculations. The cross sections of ClOOCl at wavelengths longer than 300 nm are significantly lower than all previous measurements or estimates. These low cross sections in the photolytically active region of the solar spectrum result in a rate of photolysis of ClOOCl in the stratosphere that is much lower than currently recommended. For conditions representative of the polar vortex (solar zenith angle of 86 degrees, 20 km altitude, and O3 and temperature profiles measured in March 2000) calculated photolysis rates are a factor of 6 lower than the current JPL/NASA recommendation. This large discrepancy calls into question the completeness of present atmospheric models of polar ozone depletion.
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Affiliation(s)
- Francis D Pope
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
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Hancock G, Hutchinson A, Peverall R, Richmond G, Ritchie GAD, Taylor S. 266 nm photolysis of CF3I and C2F5I studied by diode laser gain FM spectroscopy. Phys Chem Chem Phys 2007; 9:2234-9. [PMID: 17487320 DOI: 10.1039/b617414k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Frequency modulated diode laser based absorption at 1.315 microm has been used to measure the Doppler lineshapes of the I((2)P(1/2)-(2)P(3/2)) transition in atomic iodine produced from the 266 nm photolysis of both CF(3)I and C(2)F(5)I. Wavelength resolved laser gain is seen following photolysis as excited iodine atoms ((2)P(1/2)) are produced with a quantum yield close to unity from photolysis of both parent molecules. Time resolved measurements were made and the nascent speed distribution and translational anisotropy parameter, beta were determined. Mean atomic speeds of 800 and 850 ms(-1), which correspond to 83 and 68% of the maximum possible kinetic energy release into the iodine photofragment, were determined for photolysis of CF(3)I and C(2)F(5)I, respectively. The nascent translational anisotropy parameter was found to be beta = 1.77 +/- 0.05 for CF(3)I and beta = 1.69 +/- 0.05 for C(2)F(5)I. These values are explicable in terms of parent rotational motion and non-adiabatic processes in the exit channel.
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Affiliation(s)
- G Hancock
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, UK OX1 3QZ
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Eden S, Limão-Vieira P, Hoffmann S, Mason N. VUV photoabsorption in CF3X (X=Cl, Br, I) fluoro-alkanes. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.09.040] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Allan BJ, Plane JMC. A Study of the Recombination of IO with NO2 and the Stability of INO3: Implications for the Atmospheric Chemistry of Iodine. J Phys Chem A 2002. [DOI: 10.1021/jp020089q] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- B. J. Allan
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - J. M. C. Plane
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
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Bloss WJ, Rowley DM, Cox RA, Jones RL. Kinetics and Products of the IO Self-Reaction. J Phys Chem A 2001. [DOI: 10.1021/jp0044936] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- William J. Bloss
- Centre for Atmospheric Science, University Chemical Laboratories, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K
| | - David M. Rowley
- Centre for Atmospheric Science, University Chemical Laboratories, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K
| | - R. Anthony Cox
- Centre for Atmospheric Science, University Chemical Laboratories, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K
| | - Roderic L. Jones
- Centre for Atmospheric Science, University Chemical Laboratories, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K
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Atkinson DB, Hudgens JW, Orr-Ewing AJ. Kinetic Studies of the Reactions of IO Radicals Determined by Cavity Ring-Down Spectroscopy. J Phys Chem A 1999. [DOI: 10.1021/jp9902497] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Dean B. Atkinson
- Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Jeffrey W. Hudgens
- Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Andrew J. Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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Marić D, Crowley JN, Burrows JP. Application of a Gaussian Distribution Function To Describe Molecular UV−Visible Absorption Continua. 2. The UV Spectra of RO2• Radicals. J Phys Chem A 1997. [DOI: 10.1021/jp961715k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. Marić
- Institut für Sicherheitstechnologie, P.O. Box 101564, D-50455 Köln, Germany
| | - J. N. Crowley
- Division of Atmospheric Chemistry, Max-Planck-Institut für Chemie, P.O. Box 3060, D-55020 Mainz, Germany
| | - J. P. Burrows
- Institut für Umweltphysik der Universität Bremen, P.O. Box 330440, D-28334 Bremen, Germany
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Marić D, Burrows JP. Application of a Gaussian Distribution Function To Describe Molecular UV−Visible Absorption Continua. 1. Theory. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp952548b] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. Marić
- Institut für Sicherheitstechnologie, P.O. Box 101564, D-50455 Köln, Germany
| | - J. P. Burrows
- Institut für Umweltphysik der Universität Bremen, P.O. Box 330440, D-28334 Bremen, Germany
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Temperature dependent ultraviolet absorption cross sections of propylene, methylacetylene and vinylacetylene. Chem Phys 1996. [DOI: 10.1016/0301-0104(95)00401-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Fahr A, Nayak AK, Kurylo MJ. The ultraviolet absorption cross sections of CH3I temperature dependent gas and liquid phase measurements. Chem Phys 1995. [DOI: 10.1016/0301-0104(95)00172-k] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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